Inductive charging system

• US 9,419,468 B1
• Filed: 12/20/2013
• Issued: 08/16/2016
• Est. Priority Date: 12/20/2013
• Status: Expired due to Fees

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Pierson, Andrew Michael
• Primary Examiner(s): Pelton, Nathaniel
• Application Number:
  US14/136,707
• Time in Patent Office: 970 Days
• Field of Search: 320/108, 320/137
• US Class Current: 1/1
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence

Abstract

An example inductive charging system includes a housing including a first wall and a second wall opposite the first wall. The first and second walls at least partially form a channel extending along an external length of the housing. The system also includes an inductive charging coil disposed within the housing. The charging coil includes a substantially annular central axis and a wire wrapped in a spiral configuration circumferentially around the central axis. The charging coil includes a first end disposed proximate the first wall, and a second end substantially facing the first end and disposed proximate the second wall. The charging coil is positioned such that the channel passes through a gap extending from the first end to the second end.

Claims

1. An inductive charging system, comprising:

a housing including an internal portion, the housing further including a first wall, a second wall opposite the first wall, and a third wall extending from the first wall to the second wall, wherein;

the first wall, the second wall, and the third wall form a channel extending along an external length of the housing,

the first wall configured to support at least a portion of an electronic device thereon; and

an inductive charging coil disposed within the internal portion of the housing, the charging coil comprising a substantially annular central axis and a wire wrapped in a spiral configuration circumferentially around the central axis, the charging coil comprising;

a first end disposed within the internal portion and proximate the first wall; and

a second end substantially facing the first end, the second end being disposed within the internal portion and proximate the second wall, wherein the first end is spaced from the second end by a gap extending from the first end to the second end, the charging coil substantially surrounding at least a portion of the channel from within the housing such that the channel passes through the gap,

wherein a portion of the first wall comprises an alignment key indicative of a location of the first end of the coil relative to the first wall, and

wherein the charging coil is selectively energizeable to generate an electromagnetic field within the gap, the electromagnetic field being characterized by flux lines extending from the first end to the second end via the portion of the first wall.

2. The system of claim 1, wherein the charging coil comprises a central core, the wire being wrapped circumferentially around the core and the central axis extending substantially centrally through the core, and wherein the charging coil is operably connectable to a power source configured to direct electrical current to the charging coil.

3. The system of claim 2, wherein the power source is external to the housing.

4. The system of claim 1, wherein the housing comprises a shielding material configured to substantially prohibit magnetic forces from entering the housing, the first, second, and third walls being formed substantially without the shielding material.

5. The system of claim 1, further comprising:

a first sensor disposed proximate the channel and configured to determine a position of a device within the channel, a second sensor operably connected to the charging coil and configured to determine an amount of current directed to the charging coil, and a processor operably connected to the first sensor and the second sensor.

6. The system of claim 1, further comprising a display configured to output content transmitted to the charging coil.

7. The system of claim 6, wherein the electronic device comprises a rechargeable power supply, and the output comprises indicia of a level of charge of the rechargeable power supply.

8. The system of claim 1, wherein the charging coil is positioned such that the third wall is disposed radially inward of the gap.

9. The system of claim 1, wherein the electronic device includes a secondary inductive coil having a longitudinal axis, and wherein aligning the electronic device with the alignment key disposes the longitudinal axis of the secondary inductive coil substantially collinear with the central axis within the gap.

10. The system of claim 1, further comprising a display configured to output content transmitted to the charging coil, a control operably connected to at least one of the charging coil or the display, and a processor operably connected to the display and the control.

11. A computer implemented method of inductively charging an electronic device, the method performed by a processor and including the operations of:

determining the presence of an electronic device within a channel of a housing, wherein

the housing includes an inductive charging coil disposed therein, a first wall, a second wall opposite the first wall, and a third wall extending from the first wall to the second wall,

the channel extends along an external length of the housing, and is formed by the first wall, the second wall, and the third wall, and

the charging coil comprises a substantially annular central axis, a wire wrapped circumferentially around the central axis, a first end, a second end substantially facing the first end, and a gap extending from the first end to the second end, the charging coil being positioned such that the channel extends through the gap;

directing, in response to determining the presence of the electronic device, electrical current to the charging coil to generate an electromagnetic field within the gap, the electromagnetic field being characterized by flux lines extending from the first end to the second end via a portion of the first wall;

inducing electrical current in a secondary inductive coil of the electronic device with the electromagnetic field; and

charging a rechargeable power supply of the electronic device operably connected to the secondary inductive coil with the electrical current in the secondary inductive coil.

12. The method of claim 11, further comprising determining alignment of the electronic device with an alignment key of the channel, and outputting at least one of a visual signal or an audible signal indicative of the alignment, wherein aligning the electronic device with the alignment key disposes the secondary inductive coil of the electronic device within the electromagnetic field.

13. The method of claim 11, further comprising determining a level of charge within the rechargeable power supply, and outputting, via a display of the housing, indicia of the level of charge.

14. The method of claim 11, further comprising determining, with a sensor operably connected to the processor, that the rechargeable power supply has been completely charged by the electrical current, and de-energizing the charging coil in response to determining that the rechargeable power supply has been completely charged.

15. The method of claim 11, wherein:

the charging coil comprises a central core, the wire being wrapped circumferentially around the core, and the central axis extending substantially centrally through the core,

the first end comprises a first end of the core disposed proximate the first wall, and

the second end comprises a second end of the core disposed proximate the second wall.

16. The method of claim 11, further comprising directing the electrical current to the charging coil from a power source operably connected to the charging coil and disposed external to the housing.

17. The method of claim 11, wherein:

at least a portion of the housing includes a shielding material configured to substantially prohibit magnetic forces from exiting the housing, and

at least part of the first wall and at least part of the second wall are configured without the shielding material such that the electromagnetic field may be generated within the gap.

18. The method of claim 12, further comprising determining a position of the electronic device within the channel using a sensor disposed proximate the channel, wherein the sensor is operably connected to the processor and is configured to provide a signal indicative of the position to the processor.

19. The method of claim 11, further comprising adjusting the amount of electrical current directed to the charging coil using a control operably connected to the charging coil.